Automatic switch.



No. 739,205. PATENTED SEPT. 15 1903.

A J. E'. MGELROY. AUTOMATIC SWITCH.

APPLIUATION FILD JAN. 13, 1903.

F0 MODEL.` I

min-.Egg www A Vf UNITED STATES iatented September 15, y A 2 PA TENTOFFICE.

JAMES E. MCELROY, OE ALBANY, NEw YORK, AssIeNoR To ,CONSOLIDATED OARHEATING COMPANY, OE ALBANY, NEw YORK, A CORPORATION OE VES'I VIRGINIA.

AUTOMATIC SWITCH.

SPECIFICATION forming part of Letters Patent'No. 739,205, datedSeptember 15, 1903. Application fata Tammy 13, 190s. serai No. 138,917.@To model.)

To all whom it may concern:

Be it known that I, JAMES F. MCELROY, av citizen of the United States,residing at Albany, county of Albany, and State of New York, haveinvented certain new and useful Improvements in Automatic Switches, ofwhich the following' is a specification, refer-- ence being made to theaccompanying' drawings, wherein Figure 1 is a section of the switch andthe shaft by which it is operated. Fig. 2 is a plan of the same.

My invention is designed for use with a shaft which is reversedindirection at intervals and is required to simultaneously operate aswitch. In particular the invention is applicable to a dynamo driven byavehicleaxle, and hence subject to reversal of rotation, and requires asimultaneous reversal of its connection with the circuit by means of aswitch worked automatically by the shaft.

My apparatus comprises a switch that is positively thrown to one side orthe other by the engagement therewith of a pawl carried by the shaft,the engagement being controlled by a cam, which acts upon reversal ofthe shaft to cause the engagement and upon the completion of the switchmovement to break the engagement of the pawl with the switch. Referringto Fig. 1, B and B2 represent the upper and lower halves, respectively,of the dynamo-casing, while between them and inclosed thereby is thedynamo-shaft C in j ournal-box D, resting in a partition E, thattraverses a special compartment formed Within the casing for thereception ofthe bearing.

In a separate compartment at the left of the one just mentioned is thereversing-switch M. It comprises two movable blades O and O', pivoted,respectively, on the upper and lower sides of an insulating-block P on acommon axis c. The upper blade O plays between a set of opening jaws 1on the left and a similar set 2 on the right. The lower blade O likewiseplays between two sets of jaws, one being directly below the'said set 1,but not shown, and the other being the set 4, directly below set 2. Theelectrical circuits of the switch are not shown, since they are such asare well known to the art, while any other form of switch that is to beoperated in a similar manner may be employed. The outer extremities ofblades O andO are both jointed to an insulating-bar R on the axis ZJ. To

On the extremity of shaft C and rotating therewith is a flanged disk F,and directly opposite it a disk F2, integral with a stud F4, that isfree to turn in a socket g, projecting inward from a cover-plate G, thatisset into an opening in the front wall of the dynamocasing and held inplace bya spring-latch G' or by other means. The stud is secured. in thesocket bya ring-key f2. The socket g terminates in a stationary cam-diskF2, in which is a curved slot f, through which projects from disk F2 apin H, energizing the operating-bar J. Thus the oscillation of disk F2,so far as it is permitted by the curved slot and pin H, will act throughthe bar J to throw the switch M to one side or the other, and it remainsto show how the disk F2 receives such l which is on shaft C, rotates,except as it may be prevented from dropping into the Vnotch by thecam-disk F3. The cam-disk, which is stationary, has its shorter radiusabove and its longer radius below the center of stud F4. Therefore,assuming the' parts to be in the relation shown inFig. 1, when the shaftC starts to rotate in a clockwise direction the pawl K will on the firstturn drop into notch A of disk F2 and by hooking its right-hand edgedraw it around nearly a half-turn until it rides up on the lower half ofcam-disk F3, when it will be forced out of the notch and will thereaftertravel around the disks without being able to engage the notch. When,however, the rotation of the shaft is reversed, the pawl K will engagethe exposed left-hand edge of notch A, turn disk F2 in the reversedirection until it is again lifted by the cam. Of course the switch Mfollows the movements of disk F2, because of the interveningoperating-bar J.

I have found that in the device as thus far described the pawl willsometimes become loo disengaged before the throw of the switch is fullycompleted or that the switch will work back to a slight extent by thejarringof the apparatus when mounted on a car-truck, and this will causethe pawl to become battered by striking as it rotates the edge of thenotch .until Vlinally it will fail to operate the switch at the rightmoment, it being understood that the switch is ofsubstantialconstruction and requires a considerable force to throw itfrom one side to the other. To overcome this difliculty, I have provideda spring', which is put un der ltension bythe pawl simultaneo usly withits operation of the switch, and on the latter half of the stroke isreleased and allowed to act upon the switch to force it home and retainit in position with the'edge of the notch, which is well behind thecurve of the controlling-cam. The spring thus acts over a dead-center7it being powerless when the pin II is central in the slot, but operativeon each side of said center to assist the throw of the switch, as wellas the throw of the disk F2. In other words, the spring at the centralpoint has no leverage on the switch or disk, but on either side of thecenter has a gradually-increasin g leverage thereon.

Referring to Fig. l, J is a lever pivoted at its rear end to the bar Rand at its forward end bearing on a slideway G2 on the under side ofso'cket g at a point directly below the pin Il'. The lever is connectedto rod J by a strong spring S, and of course travels to and fro with therod. It will be manifest that as the pin H moves in either directionover the latter half of the arc formed by the curved slot f it will beassisted in its movement by spring S, which is put under tension duringthe progress of the pin over the first half of the arc. This will tendto throw the disk F2 to the full end of its stroke and force the leadingend of the notch A well behind the enlarged portion of the cam, where itis not exposed to engagement by the pawl K. It also serves to force theswitch-blades home into the jaws and retain them there, since it exertsat the end a strong leverage on the blades, the pin II at such timescoming nearly to a dead-center with respect to rod J. The same action isrepeated at each end of the stroke.

It will be understood that the apparatus shown herein is butA anillustration of the invention, being that form thereof which I nowregard as the best out of the various forms in which the principle ofthe invention may be embodied.

lVhat I claim as new, and desire to secure by Letters Patent, is-

l. The combination with a dynamo-electric machine of a reversibledriving-shaft therefor, a reversing-switch, a pawl for operating theswitch by the movement of the machine, a notched disk engaged by thepawl and a cam for disconnecting the pawl from the disk at apredetermined point.

2. The combination with a dynamo-electric machine of a reversibledriving-shaft there-v for, a reversing-switch, a disk connected to theswitch and provided with a notch in its periphery, a pawl carried by thedynamo-shaft adapted to engage the said notch and a cam for disengagingthe pawl at a predetermined point.

3. The combination with a dynaino-electric machine, of a reversibleshaft therefor, a reversing-switch, a rotating pawl driven by the shaftand movable radially with respect to its center of rotation, an engagingdevice connected with the switch and lying in the path of thepawl, andan automatic disengaging device dependent on the throw of the switch.

fi. The combination with armature-shaft C of a reversing-switch, a diskF, a pawl K, notched disk F2 connected to the reversingswitch and astationary cam-disk F3.

5. The combination with a shaft reversible in direction and areversing-switch, of an intermediate pawl and engaging device, the oneconnected to the switch and the other to the shaft so as to rotatesynchronously therewith, and automatic disengaging devices dependent onthe throw of the switch.

G. The combination with a shaft adapted to rotate continuously in eitherdirection, of a switch operated thereby, engaging devices interveningbetween the shaft and switch, means for limiting the engagement period,a switch-operating spring, and leveragechanging devices for the springwhereby the spring' acts upon the switch over a dead-centerl 7 Thecombination with a shaft adapted to rotate continuously in eitherdirection, of a switch operated thereby, an engaging device acting forboth directions of the shaft to con= neet the shaft with the switch,means for limiting the engagementv period, a switchoperating spring, andleverage-changing devices for the spring, whereby the spring acts uponthe switch over a dead-eenter- 8. The combination with a dynamo drivenin reverse direction by a car-axle', of a reversing-switch therefor, anengaging device between the dynamo shaft and the switch, means forlimiting the engagement period, a switch-operating spring, andleverage-changing devices whereby the spring acts upon the switch over adead-center.

9. The combination with a reversible rotating shaft, of a switchoperated thereby, a pawl carried by the shaft, a part connected to theswitch .and engaged by the pawl at starting, means for disengaging thepawl when the switch is thrown, a switch-operating spring, andleverage-changing devices whereby the spring acts upon the switch over adead-center.

10. The combination with a dynamo driven in reverse directions by acar-axle, of a reversing-switch therefor, a rotating engagement devicedriven by the axle and a corresponding engagement device connccted withthe switch, a disengaging cam, a spring act-= IIO IZO

ing on the engaging devices in the-direction of their joint movement tosupplement the action of the cam.

11. The combination with a reversible dynamo-shaft, of areversing-switch for the dynamo, a pawl for engaging the shaft with theswitch, operating devices for the switch moving in an arc, aswitch-operating spring, and leveragechanging devices whereby the springacts upon the switch over a dead-center.

12. The combination with a reversible dynamo-shaft of a reversingswitch, 'a pawl carried by the shaft, a rotatable notched disk connectedwith the switch and engaged by said pawl, a cam controlling theengagement of the pawl and disk, and a spring put under tension by theshaft and acting on the said disk when the pawl is disengaged by thecam.

13. The combination with a switch of an operating-rod therefor runningat one end in an arc, a rotating shaft, engaging devices between saidrod and shaft7 means for limiting the period of engagement, a levermoving with the switch in a right line and a spring between said leverand said rod.

11i. The combination with a reversible dynamo-shaft of a reversingswitchoperated thereby, a pawl K, notched disk F2 connected with the switch bya rod J, a cam F3 controlling the length of engagement-pawl K with diskF2, a lever J, a guide G2 therefor and spring S between said rod J andlever J.

In witness whereof I have hereunto set my hand, before two subscribingwitnesses, this 10th day of January, 1903.

JAMES F. MCELROY.

Vitnesses:

WILLIAM A. MoRRILL, J r., BEULAH CABLE.

